| 摘要 |
PURPOSE:To improve the withstand voltage between the collector and emitter by a method wherein an impurity layer becoming a part of the base is formed on the side surface of the film at the time of forming a field oxide film. CONSTITUTION:A buried layer 22, an epitaxial layer 23, and a peroxide film 24 are formed on an Si substrate 21. Next, after depositing an Si nitride film, Si nitride film patterns 261 and 262 are formed by etching with resist patterns 251 and 252 as the mask. Then, after forming a boron ion implanted layer 27 by ion- implanting boron, anisotropic etching is performed with the Si nitride film patterns 261 and 262 as the mask. At the time, a p type diffused layer remains in the Si layer 23 on the etching side surface. The field oxide film 29 is formed by selective oxidation, and a p type diffused layer 28' is formed. Thereby, an element region consisting of two island parts 301 and 302 is formed, and the p type diffused layer 28' becomes a part of the base. |
